[bug] put a monkeypatch back for bigcouch

Current code was tested on couch 1.6 and a monkeypatch got removed
during refactor. This commit re-adds it, but in a separate module that
is intended to hold temporary code for compatibility that can be removed
on version upgrades.

2 files changed, 119 insertions, 4 deletions

diff --git a/common/src/leap/soledad/common/couch/__init__.py b/common/src/leap/soledad/common/couch/__init__.py
index bd8b08b7..fb3d57af 100644
--- a/common/src/leap/soledad/common/couch/__init__.py
+++ b/common/src/leap/soledad/common/couch/__init__.py
@@ -33,7 +33,6 @@ from multiprocessing.pool import ThreadPool
 
 
 from couchdb.client import Server, Database
-from couchdb.multipart import MultipartWriter
 from couchdb.http import (
     ResourceConflict,
     ResourceNotFound,
@@ -53,6 +52,7 @@ from u1db.remote import http_app
 from leap.soledad.common import ddocs
 from .errors import raise_server_error
 from .errors import raise_missing_design_doc_error
+from .support import MultipartWriter
 from leap.soledad.common.errors import InvalidURLError
 from leap.soledad.common.document import ServerDocument
 from leap.soledad.common.backend import SoledadBackend
@@ -692,8 +692,7 @@ class CouchDatabase(object):
             couch_doc['_rev'] = old_doc.couch_rev
         # prepare the multipart PUT
         buf = StringIO()
-        headers = {}
-        envelope = MultipartWriter(buf, headers=headers, subtype='related')
+        envelope = MultipartWriter(buf)
         envelope.add('application/json', json.dumps(couch_doc))
         for part in parts:
             envelope.add('application/octet-stream', part)
@@ -702,7 +701,8 @@ class CouchDatabase(object):
         try:
             resource = self._new_resource()
             resource.put_json(
-                doc.doc_id, body=str(buf.getvalue()), headers=headers)
+                doc.doc_id, body=str(buf.getvalue()),
+                headers=envelope.headers)
         except ResourceConflict:
             raise RevisionConflict()
         return transactions[-1][1]
diff --git a/common/src/leap/soledad/common/couch/support.py b/common/src/leap/soledad/common/couch/support.py
new file mode 100644
index 00000000..bfc4fef6
--- /dev/null
+++ b/common/src/leap/soledad/common/couch/support.py
@@ -0,0 +1,115 @@
+# -*- coding: utf-8 -*-
+# support.py
+# Copyright (C) 2015 LEAP
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+import sys
+
+
+"""
+Monkey patches and temporary code that may be removed with version changes.
+"""
+
+
+# for bigcouch
+# TODO: Remove if bigcouch support is dropped
+class MultipartWriter(object):
+
+    """
+    A multipart writer adapted from python-couchdb's one so we can PUT
+    documents using couch's multipart PUT.
+
+    This stripped down version does not allow for nested structures, and
+    contains only the essential things we need to PUT SoledadDocuments to the
+    couch backend. Also, please note that this is a patch. The couchdb lib has
+    another implementation that works fine with CouchDB 1.6, but removing this
+    now will break compatibility with bigcouch.
+    """
+
+    CRLF = '\r\n'
+
+    def __init__(self, fileobj, headers=None, boundary=None):
+        """
+        Initialize the multipart writer.
+        """
+        self.fileobj = fileobj
+        if boundary is None:
+            boundary = self._make_boundary()
+        self._boundary = boundary
+        self._build_headers('related', headers)
+
+    def add(self, mimetype, content, headers={}):
+        """
+        Add a part to the multipart stream.
+        """
+        self.fileobj.write('--')
+        self.fileobj.write(self._boundary)
+        self.fileobj.write(self.CRLF)
+        headers['Content-Type'] = mimetype
+        self._write_headers(headers)
+        if content:
+            # XXX: throw an exception if a boundary appears in the content??
+            self.fileobj.write(content)
+            self.fileobj.write(self.CRLF)
+
+    def close(self):
+        """
+        Close the multipart stream.
+        """
+        self.fileobj.write('--')
+        self.fileobj.write(self._boundary)
+        # be careful not to have anything after '--', otherwise old couch
+        # versions (including bigcouch) will fail.
+        self.fileobj.write('--')
+
+    def _make_boundary(self):
+        """
+        Create a boundary to discern multi parts.
+        """
+        try:
+            from uuid import uuid4
+            return '==' + uuid4().hex + '=='
+        except ImportError:
+            from random import randrange
+            token = randrange(sys.maxint)
+            format = '%%0%dd' % len(repr(sys.maxint - 1))
+            return '===============' + (format % token) + '=='
+
+    def _write_headers(self, headers):
+        """
+        Write a part header in the buffer stream.
+        """
+        if headers:
+            for name in sorted(headers.keys()):
+                value = headers[name]
+                self.fileobj.write(name)
+                self.fileobj.write(': ')
+                self.fileobj.write(value)
+                self.fileobj.write(self.CRLF)
+        self.fileobj.write(self.CRLF)
+
+    def _build_headers(self, subtype, headers):
+        """
+        Build the main headers of the multipart stream.
+
+        This is here so we can send headers separete from content using
+        python-couchdb API.
+        """
+        self.headers = {}
+        self.headers['Content-Type'] = 'multipart/%s; boundary="%s"' % \
+                                       (subtype, self._boundary)
+        if headers:
+            for name in sorted(headers.keys()):
+                value = headers[name]
+                self.headers[name] = value